Hydraulic torque vane-type motors



Jan. 22, 1957 o. GREELEY 2,778,340

HYDRAULIC TORQUE VANE-TYPE MOTORS Filed March 13, 1953 IE |o I4 j l5 1e Z2 Z5 38 FIG. 1 6OIII J 6! 23 24 39 35 //i 50b LEO O. glxE wToR 500. My 48 BY ATTORNEY Sta e??? 51 HYDRAULIC TORQUE VANE-TYPE MOTORS loo 0. Greeley, "Cadillac, Mich, assignor to F. J.

McCarthy, Inc, Cadillac, Mich., a corporation of Michigan Application March 13, 1953, Serial No. 342,236

'6 Claims. (Cl. 121-38) This invention relates to torque motors and more particularly to a motor specifically designed for effecting reciprocal, semi-circular movement of a central rotor under severe operating conditions.

My torque motor is specifically designed to produce reciprocating, rotative motion through an are somewhat less than 180. It is designed to do that while generating high torque values on the rotor. In addition, the unit is designed to be of exceedingly simple construction whereby the possibility of operational failure is reduced to a minimum. It also has the purpose-of reducing the overall size of the motor to make it a compact unit, permitting its installation and use with a minimum of available space. The unit is designed .for operation under ad- 'verse conditions where it will be constantly exposed to abrasive dirt, water and corrosive substances such as salt and calcium chloride. It is particularly designed as a compact unit for actuating the scraper blade of road grading and maintenance equipment. This type of operation involves all of the adverse conditions mentioned besides requiring a unit which will not be adversely affected by vibration and shock.

These and other objects and purposes of my invention will be understood by those acquainted with the design of road maintenance equipment and those acquainted with the design of hydraulic actuating devices upon reading the following description and the accompanying drawin s.

In the drawings:

Fig. 1 is a plan view of my torque motor with one-half of the motor centrally sectioned.

Fig. 2 is an end elevation of my torque motor.

Fig. 3 is a sectional elevation view of my torque motor taken along the plane IIIIII of Fig. 1.

Fig. '4 is a fragmentary sectional view taken along the plane IVlV of Fig. 3.

Fig. 5 is an enlarged fragmentary view of one of the vanes for my torque motor.

My torque motor includes a shell designed to be rigidly secured to a supporting structure whereby it will be stationary with respect to a rotor extending through the shell and having a stud shaft projecting from each end through the caps closing the ends of the main shell. The rotor is of such diameter that it creates a relatively narrow annular chamber between the housing and the rotor. The rotor is provided with a pair of diametrically spaced slots in which are mounted plastic vanes extending across the annular chamber and pressing against the inside surface of the housing or shell. The housing is likewise provided with a pair of longitudinally extending, semi-circular channels in which are seated similar vanes eflecting a seal against the rotor. Then vanes divide the annular chamber into two pairs of operating chambers, one pair to effect rotation in each direction.

Referring to the drawings in detail, the numeral indicates a generally tubular, elongated shell of sufficient wall thickness to withstand high operating pressures. The shell 10 serves as the stator of the motor. The internal opening through the shell is circular in cross section and forms the outside wall of the hereinafter described 'annular chamber. Extending the full length of the top of Patented Jan. 22, 1957 the shell 10 are a pair of spaced bosses 11 each having a plurality of threaded holes 12. The threaded holes 12 provide means whereby the shell 10 maybe secured toits supporting structure through suitable bolts.

Each end of the shell 10 is closed by an annular cap 13. Each of the caps 13 has a channel opening toward the shell 10 in which is seated a seal 18 to prevent the escape of fluid through this joint. The cap 13 has a peripheral lip 14 seating into an external channel 15 at each end of the housing. The caps 13 are secured to the shell by means of the bolts 16, each one extending into an internally threaded boss 17 in the end of the shell (Fig. 4). The bolts are equally spaced around the ca and are located at frequent 'intervals to sustain the high operating pressures for which the torque motor is designed. The caps 13 are counterbored from each end, the outer counterbore 24 being larger than the inner counterbore 20 and separated therefrom by the flange 22. Seated within the inner counterbore 20 is a sleeve bearing 21. At the outer end of the inner counterbore 20 and between the end of the bearing 21 and the flange 22, is a sealing ring 23. The sealing ring 23 prevents the escape of fluid from within the torque motor. Seated within the outer counterbore 24 is a dirt seal 25.

Seated within the shell 10 is a rotor 30. The body of the rotor, being that portion of it within the shell 10, is of such diameter that only a narrow fluid chamber 31 remains between the rotor and the shell. From each end of the main body ofthe rotor 30 extends a shaft 32 of constant diameter where it passes through the bearing 21, the sealing ring 23 and the dirt seal 25. Externally of the dirt seals 25, the shafts 32 taper and their outer ends 33 are threaded for the reception of a'washer 34 and nut 35. The tapered portions of the shafts 32 are each provided with a'keyway 36 (Figs. 1 and 2) for reception of a key.

The collar 38 has a tapered internal opening permitting it to seat snugly about the shaft 32 and be coupled to the shaft by a key seated in the keyway 36. The collar 38 is surrounded by a thick layer of rubber forming a flexible coupling 39. The flexible coupling 39 is rigidly secured to the collar by suitable means such as vulcanizing or adhesives. The means to be actuated by the rotor 30 has a collar '40 seating over the flexible coupling 39 and secured to the coupling by suitable adhesives or by vulcanizing to prevent relative movement between this collar 40 and the flexible coupling 39. 1 p

The shell 10 is provided with a pair of diametrically spaced, semi-circular'channels 44 extending the full length of the shell and opening into the central chamber 31. In the area of the channels 44, the outer Wall of the shell 10 is outwardly shaped producing an outwardly extending, rounded boss 45 (Fig. 3) to assure suitable wall thickness in this area to sustain the operating pressures of the torque motor. The channels 44 are located substantially on the horizontal centerline of the central chamber 31. Seated in each of the channels and extending the full length of the housing It is a vane or rod 46 of circular cross section. The rods 46 are slightly longer than the housing 10. When the caps 13 are bolted into place the ends of these rods will be slightly compressed, assuring a fluid tight seal at each end of the central chamber 31. The diameter of the rods 46 is such that they substantially occupy the channels 44, extend across the central chamber and contact the surface of the rotor 30. The exact relationship between the rods 46 and the channels 44 will be described in a subsequent paragraph.

Channels 47, identical to the channels 44, are provided in the rotor 30. The channels 47 are located diametr-ically opposite each other and each seats a vane or rod 48 identical to the rods 46 in diameter, composition and length.

Thechannels 44 and 47 are each of a slightly greater diameter than the rods 46 and 48. This leaves a pocket or gap 49 (Fig. not exceeding approximately five thousandths of an inch between one side of the rod and the wall of the channel. This gap tapers to nothing in approximately an arc of one fourth the circumference of the rod. The purpose of this gap is to permit bydraulic fluid to flow between the rod and the wall of the channel on one side of the rod and to force the rod tightly against the opposite wall of the channel and to flatten the rod slightly. This flattening of the rod causes it to press tightly against the opposite wall of the internal chamber 31. This produces a tight seal between the chambers created by the rods. The tightness of the seal increases as the pressure of the hydraulic fluid increases.

It has been found that as the rotor moves the rods do not slide along the opposite wall of the chamber but rotate in their channels. This rotation is facilitated by an extremely thin film of oil between the rod and the channel. As the rod rotates, the axis of elongation across the operating chamber remains fixed on a radius of the rotor. Therefore, as the rod or vane rotates, the axis of elongation passes around the rod causing constant flexing of the rod.

It will be recognized that to effect this deformation of the rod, the rod must be made of a material having plastic qualities capable of temporary and changing deformation Without permanent change of shape. The plasticity of the rod is also necessary to permit the compression of the rod when the caps 13 are bolted into place.

It is possible, but not as desirable functionally, to substitute steel for the plastic material in the rods. Since steel rods cannot be axially compressed they must be manufactured to precise tolerances in length to prevent leakage about their ends. 'This is a costly operation made unnecessary by the use of a plastic material. Since the cross section of the steel cannot be deformed, it is also necessary to maintain extremely close tolerances on the inner surface of the shell 10, the surface of the rotor 30 and the surface of the rods.

This again substantially increases fabrication costs. If precise surfaces are maintained, the rods will be caused to press tightly againstthe opposite Wall of the operating chamber by reason of the fluid acting in the gap 49.

The rods or vanes 46 and 48 divide the central chamber 31 into two pairs of operating chambers these being the chambers 50a and 50b. The chambers 50a are interconnected by a passageway 51 extending diametrically through the rotor 3!) (Figs. 1 and 3). The chambers 50b are interconnected by a similar passageway 52 (Fig. 3). The passageways 51 and 52 are located, one on each side of the longitudinal centerline of the'rotor.

The shell has a boss 60 on each side at its longitudinal center. Through each boss passes a port communicating with the central chamber 31. The ports are located above and immediately adjacent the rods 46. The port 61 communicates with the operating chambers 50a. The port 62 communicates with the operating chambers 56b. The ports 61 and 62 are designed to operate alternately as inlet and outlet ports for the hydraulic fluid. The ports 61 and 62 are internally threaded to receive a suitable end coupling for the hydraulic lines connected to them.

The various parts of my torque motor including the shell, the rotor and the caps are preferably fabricated from steel and the face of the rotor 34] and the inside face of the shell 10 are machined to a smooth finish to eliminate excessive wear and friction.

Operation My torque motor is designed to be operated by hyof 200 to 1500 p. s. i. depending upon the amount of torque it is desired to develop. Considering the operatiug chambers to be filled with hydraulic fluid, if it is desired to move the rotor clockwise, as it appears in Fig. 3, hydraulic fluid is introduced through the port 62. Some of the fluid will enter into the space between the rods 48 and the walls of the channels 47 and between the rods 46 and the walls of the channels 44. As the'pressure increases this will eflect a positive seal between the rods 48 and the shell 10 and the rods 46 and the rotor 39. The reaction of the hydraulic fluid upon the rods or vanes 46, held stationary with respect to the shell 10, will cause an equal and opposite reaction upon the rods 48 which reaction will result in clockwise rotation of the rotor. As the rotor moves, the operating chambers 50a will contract, forcing the fluid in these chambers to be discharged through the port 61.

Movement of the rotor is limited to an arc of somewhat less than 180. The rotor does not traverse an are so great. that the rod 48 travelling toward the port 61 crosses the port 61. Rotation of the rotor may be stopped at any point in its travel and the rotor held stationary by providing balanced pressure valves in all four of the operating chambers. If the liquid in all of these operating chambers is valved against escape, the rotor cannot move since hydraulic fluid is substantially incompressible and will hold the rotor against movement as if they were embedded in a solid material.

When it is desired to return the rotor to its original position, hydraulic fluid is introduced through the port 61 filling the operating chambers 50:: and the hydraulic fluid in the operating chambers 50!; is exhausted through the port 62. Thus, it will be seen that the rotor may be reciprocated with equal torque in either direction. The passageways 51 and 52 assure a balance of pressure between the operating chambers forming eachpair.

By reason of the rotors large diameter, the operating chambers 56a and 50b are relatively narrow. They, therefore, operate upon a small volume of fluid. This is desirable because it permits rapid operation of the rotor when desired. It also permits operation of the torque motor by hydraulic systems having a limited supply of fluid. This is particularly important where the torque motor is to be used on trucks and similar portable equipment because their'facilities for storing and pumping hydraulic fluid to high pressures is limited. At the same time because of the relatively large diameter of the rotor, an appreciable moment arm is provided for the forces acting against the vanes or rods 48. Thus, a fairly sizable torque motor may be built according to my invention which will operate upon a minimum quantity of fluid yet developing substantial torque due to the moment arm created by the size of the rotor.

The use of a rotor of relatively large diameter permits the use of long rotors without deflection. Where it is desired to increase the torque without increasing the operating pressure, the length of the motor may be increased. Substantial latitude is permitted by the large diameter rotor design in obtaining additional torque by this means. 7

It will be recognized that my invention is relatively simple to construct having a minimum of machined parts and being suitable for rapid assembly. The motor, because of its'simplicity and adaptability to rugged construction, is suited to operation under adverse conditions since it will not be particularly affected by vibration or shock. This is particularly desirable for equipment designed for use upon road maintenance'machinery.

Various modifications ofmy invention may be made each without departing from .the principle thereof. Each of these modifications is to be considered as included in the hereinafter appended claims unless these claims by their language expressly state otherwise.

1 claim:

1. A torque motor comprising: an elongated housing having a circular, elongated central chamber therein; a rotor of circular cross section journaled in each end of said housing; said rotor having a diameter in excess of a major portion of the diameter of said central chamber; a pair of diametrically positioned channels in said housing, opening into said central chamber and extending the length thereof; a pair of diametrically positioned channels in said rotor, opening into said central chamber and extending the length thereof; a rod-like compressible plastic vane seated in each of said channels, said vanes each having an approximately equal cross sectional height and width and being of suflicient cross section to extend between said housing and said rotor for dividing said central chamber into two pairs of operating compartments; a pair of fluid ports, each communicating with one of said pairs of operating compartments; the portions of said vanes seated in said channels of said rotor and of said housing being of lesser cross sectional area than said channels whereby a gap is defined between said vanes and the walls of said channels, said gap communicating with said chamber for receiving the fluid operating said motor and compressing said vanes against a portion of the walls of said channels and the opposite wall of said chamber.

2. A torque motor comprising: an elongated housing having a circular, elongated central chamber therein; a rotor journaled in each end of said housing; said rotor having a diameter equal to a major portion of the diameter of said central chamber; a pair of diametrically positioned channels in said housing, opening into said central chamber and extending the length thereof; a pair of diametrically positioned substantially semi-circular channels in said rotor, opening into said central chamber and extending the length thereof; a plastic vane of circular cross section seated in each of said channels, said vanes having a diameter sufficient to extend between said housing and said rotor for dividing said central chamber into two pairs of operating compartments; a pair of fluid ports, each communicating with one of said pairs of operating compartments; said vanes and a portion of the walls of said chambers defining a pocket communicating with said chamber whereby fluid pressure in said pockets will compress said vanes against a portion of the walls of said channels and the opposite wall of said chamber.

3. A torque motor comprising: an elongated, tubular housing having a central chamber of circular cross section extending therethrough; caps mounted on each end of said housing; a rotor of circular cross section extending through said central chamber and rotatably sup ported by each of said caps; said rotor having a diameter in excess of a major portion of the diameter of said central chamber; a pair of diametrically positioned channels in said housing, opening into said central chamber and extending the length thereof; a pair of diametrically positioned channels in said rotor, opening into said central chamber and extending the length thereof; a rod-like compressible plastic vane seated in each of said channels, said vanes each having an approximately equal cross sectional height and width and being of sufficient cross section to extend between said housing and said rotor for dividing said central chamber into two pairs of operating compartments; a pair of fluid ports, each communicating with one of said pairs of operating compartments; said rods being slightly longer than said housing whereby they are axially compressed upon installation of said caps.

4. A hydraulically operated torque motor comprising: an elongated housing having a circular, elongated central chamber therein; a rotor journaled in each end of said housing; said rotor having a diameter equal to a major portion of the diameter of said central chamber; a pair of diametrically positioned channels in said housing,

opening into said central chamber and extending the length thereof; a pair of diametrically positioned substantially semi-circular channels in said rotor, opening into said central chamber and extending the length thereof; a plastic vane of circular cross section seated in each of said channels, said vanes having a diameter sufiicient to extend between said housing and said rotor for dividing said central chamber into two pairs of operating compartments; said vanes having a diameter less than the diameter of said channels whereby fluid may enter between said vanes and a portion of said channels for pressing said vanes against the remaining portions of said channels and the opposite wall of said central chamber; a pair of fluid ports, each communicating with one of said pairs of operating compartments.

5. A hydraulically operated torque motor comprising: a rotor; a first pair of axially extending, diametrically positioned channels of semi-circular cross section in the face of said rotor; a first compressible vane of circular cross section seated in each of said channels; a tubular housing, closed at each end, radially spaced from and surrounding said rotor for defining an annular chamber therebetween; the inside surface of said housing contacting said first vanes; a second pair of axially extending, diametrically positioned channels of semi-circular cross section in the inside face of said housing; a second compressible vane of circular cross section seated in each' of said channels;-each of said second vanes contacting said rotor; said first vanes and said second vanes dividing the space between said rotor and housing into two pairs of operating compartments; said first vanes and said second vanes each having a diameter less than the diameter of said channels whereby fluid may enter between said vanes and a portion of said channels for pressing said vanes against the remaining portions of said channels and the opposite wall of said annular chamber; a pair of ports for hydraulic fluid, one of said ports communicating with each of said pairs of operating compartments; a pair of conduits through said rotor; each of said conduits forming a passageway between the members of one of said pairs of compartments.

6. A hydraulically operated torque motor comprising: an elongated housing having a circular, elongated central chamber therein; a rotor journaled in each end of said housing; said rotor having a diameter equal to a major portion of the diameter of said central chamber; a pair of diametrically positioned channels in said housing, opening into said centralchamber and extending the length thereof; a pair of diametrically positioned substantially semi-circular channels in said rotor, opening into said central chamber and extending the length thereof; a vane of circular cross section seated in each of said channels, said vanes having a diameter sufficient to extend between said housing and said rotor for dividing said central chamber into two pairs of operating compartments; said vanes having a diameter less than the diameter of said channels whereby fluid may enter between said vanes and a portion of said channels for pressing said vanes against the remaining portions of said channels and the opposite wall of said central chamber; a pair of fluid ports, each communicating with one of said pairs of operating compartments.

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